SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54cf6cf459eb9e70cb3e88347e5d9a3ac6184005d830e77b848e617843986734' 
  AND token = 'ol1g5IQ0EvqYpWzQklgsxFK+ASwn3YLNqwVPkjgw+JA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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