SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18b00449035cf1098956961581eaaaa79a8e06022f33bfd3f5fbb04ae829a439' 
  AND token = 'AraCKWGBHaZXNMZmzFUYSgqRCpAJaBkkHPXv5k/+Z5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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