SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48f29c932f44876774f9df2b271685abfd475405b2035db72f2c2c14c916c664' 
  AND token = 'wxEnfDMoGgeU02uKLLpr3t1x6wzg+up1sc/odG+tMDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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