SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69115f711a0cf7abb1f03a6d8a498a026614ad70d4f764b41edbe4da4db5a04f' 
  AND token = 'JYJj3KLqcjHI7a4LAsKCrKZeyNKu4DccRbaj0KwFuGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}