SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27574d5c09c936f8bb44e991f6d4340240178f493394f7d49f2a9fd10ca6f610' 
  AND token = 'ClNVHS1TjRqGXsg++dc52lAtZtzJP7YvthSyM4PzEX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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