SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44b913ba177498b211d19338614b2406d70d68fae510f5bb3134ffb05bc0e138' 
  AND token = 'zY3yzJ4fMLtda/fmKXQY8gUDhovbggz4+CVA6jvmN+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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