SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '033a51c414d2414523122a3e862d6f5b85a8c2f2164385d167f3a08247923389' 
  AND token = 'UWCn89FYrOd+ISZ+liD4Fc/PwyuwwUHGYvTPWz0sbaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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