SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '317e77a496b42f38c8e90cae161feb387c8004352b58cc105b62af374929db27' 
  AND token = 'LweBePQ9OsP8Y/hWZj1nLDdmZUYE43HifVvuzmO3tsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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