SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25194973cc51bb72df7e83b7248cb81488b7f1104bb042ba68875be329c99edf' 
  AND token = 'ozGnK4NYrjMHKcCTHKFIr5+sUprlAJfRirYHf6ZiOwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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