SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18fcf9712dad03f95f283dc86c3a67d42b12f990fea7d11d4c79a6896a75c92b' 
  AND token = 'jap0JZqCVJeqQuQFw52VuKP/C9SkRP3Ei3psHqYqG1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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