SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd77cfb6f6b0423384e039412371c1a5b676c7d3fe0c5f834962368ead4dda7f' 
  AND token = 'KGzB03kFFb1uP5MfviMGDzx88hQAMLfX/UlEkQpGwUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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