SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad315bc82aabd497c7f99f13e343cef9c763d1f95a0a382cebfa402ddeda1190' 
  AND token = '+azWjzR2o+SmTq59OWHVQXSbt9iSQ7cV5hCSjW6CtQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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