SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c38396997d9f8f1e31211cb855654bd7c280e86992f1306be6d96d9ed3abfc67' 
  AND token = 'n4qDWO8fCBplgveSOuY6dv6NfnQrFQHHXYhTLP1+a6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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