SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1e00f6dea6caa8be000ff5d51ad2666b14f09c94ce45ed329ea4ea32d499de4' 
  AND token = 'McGkagSJtppVZGcQkwqPcPSKsE8CeB5O/1jjp1O/ojo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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