SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec59233d6968547892f5e5b11fa91b0153cedf87fcd4fbfff5b8d8981da8c1ea' 
  AND token = 'tFb5eXJvWPBmgr8FF0TdvP1QjQWEfZFOc8Di6GL7daU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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