SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c000cd8d53fcc996ad23585f439090bb4bfce2b8a4bb79d96381713651b5c6e' 
  AND token = '61oqctvvBnugFYmM6XFAe2/I+A6xSovblgq4nsfrhLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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