SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd91065f74b83abe9c54a0bd292e44951e302fd7f4602e2eeff170434bb09a145' 
  AND token = '78lPF4f/zHRMryRUH5hIZrGcj4ATRQ5eCjyQzb9wuv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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