SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da1748baba242d5ac2ce832be082da3d2bac540c6156610f0be36eca2f791abb' 
  AND token = 'EzKxwLjsn+6X/gZMSr6FDLTevbexf7RXstonjcVbwmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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