SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ee8cc0b24d9de3d83b789d84559396e6446f7046f43ed970553e02c197be667' 
  AND token = 'MltUqZUn9Ky/aFYzzWgo15emV5JkWuwh1tIB/UFRe6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}