SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a6f4b066da76e282158d5f3953c1b6200a8cccfb26f35c22d1120b423377c0' 
  AND token = 'KcV9eM0nND2CnpY5KFX57TyF470gTBLT9e1n0vPaUWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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