SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1354ec9b3ab6c53be06a9792bac81ffb7020373ddd317197fa28bb8a67dc08a6' 
  AND token = 'AisYWqvgxjGZxazDAbr53+kjs2jI7fTZBMDfqsEUmBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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