SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e1197393b3bbe01e5af358c036902d70845b07993fd66d16eb52ebb3ba21fa2' 
  AND token = 'Txgzshn4JCa2vsGVzRnTVlPkVBc/QMsvPpDo8sJlrRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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