SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec8db740f8207d58f39dce507e9ce297cb3e221485279af83a8997bef4b02a0c' 
  AND token = 'SmjmmrYU7DpyDeaFNe2gCKsztdcZQgtbEWgDXEcD2PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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