SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b87f9e766d5cd70ebdd99f87d8bd9165d2edd527f1d1460d51d0817e343ae616' 
  AND token = 'gSD1P+f7d2+bFfhuin/QRetxzKIU8vlDXCX0tYFTVEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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