SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ce1abd6bc3239ef3d28483053b232a4dc338fa543bc713cf981e30ac7010051' 
  AND token = 'a1dBcdFXsilqVAtFDZV4gtZRDn/jU4FkvTDUjoV7NXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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