SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25e599b6cb47048f89a693864fea38f8094d255505fcd4d30ca547d6651180e6' 
  AND token = 'Y/aLT9CPTQrWmDRvDvSQ6v2SBONRD9M/TXoPkVo6WnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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