SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cce37848396e523f9c6dad475fd129e1918ffb1267599922b2a51effb66b020' 
  AND token = 'gSHTDxcq8742qKyhzBeK/3sBTnDxzbTXHXpIKPvV10Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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