SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfd3459eae55b835f196ef595910235e86fff723a9aae70725343b160f67e96e' 
  AND token = 'JBGrTAw7YM9LdfxgzoVFBdIJwYRAPk1jbw/aL3PqO9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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