SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef6c63beae903131ebd80d130f86dab0ccaef61ef53741ace14ee46f640fb143' 
  AND token = 'SAsldbKAxNdoYo/sBb308t4xevhVE3dFnLIfjtQiOws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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