SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ac1aef139bc169d220061b9257a16cabeb21d099490bf354acb0b913de16ab2' 
  AND token = 'KcIva+1jK1Nzx7aZDbdA8YbZVhGdicyK3D72eKdDwfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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