SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebbe27796463864192566dcc55cd1762432f64b3ba8fc1c37160025f8ebcc231' 
  AND token = 'EbebVmK9Tk0P02NUPWfxgjdsAb354QrSycdCeIFQBFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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