SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd420a033bfe970e5437638a869a298e91208f2421ff6f747f189d7d13bfd6e23' 
  AND token = 'cU97E+9eG26IYrKCsiGaqbtbwZpd51jJ+OmnJ47kmyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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