SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ad6ec74f62059d8501d00bbc4b31dbc3cf974652662f5a7ecfa08e3c9196691' 
  AND token = '73d+wX/J24RhogvHQKQ0RpkqGkGBdhHeVtCK2J/2Qa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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