SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec3da80981fb85b4f0ad3db1c4717d6c9a6f231bd6fbdcfcf726c816c6d13a1f' 
  AND token = 'eL0qgdTzjP2StNtCERcNpkra9nsMbwjAaFIvb1av3tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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