SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '996861e7f27a1220be87b87a3db466d0f70d8a11a68248a1c21ef937d02c70ae' 
  AND token = '7LW1M+ke6wCRZM753TkEAvmM8GkAZM58SextHOdKPew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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