SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dc46e531bdb52a416c09f0c816af878c7ac3b6c569ab0ffd92c0919ea980393' 
  AND token = 'ScZRmqy1ibH4W+GqNP8Uglkl4R0zanSZSoUkBNKAiBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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