SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b650497e66d78e52ba4378ffcdfca4fc955a4d94a65e77b91c56ec5fae7aca8' 
  AND token = 'iuwRfnrYEasbWGv+KsJLxDpJqoPJYr9mu0Hwyfhzrzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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