SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '178b10e63e84d6504cf3169c64cd4de954250006e910befc25684859850c35aa' 
  AND token = 'OFIB3/+KO1cRYspr7T9kGAJ6FnozebSM6cvydBlJ6hQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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