SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df7ad2bceb3cbcdae75ef87fd5f809eb881654c82c9bc2dda1399d477382527f' 
  AND token = '8nFqmrqupgZDKYxb8nmhLTZ8vh2fVpeu0hmKCR23rTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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