SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01303766b5d59fcdca71f2fba762f8966bac2893340a3a8861caf75d57a86345' 
  AND token = 'j9UIcLnoJpwCzi+bLaaH4FBbH1pqttNmxjAs7xzg3D0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}