SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb78696363a0b09a06ce4b4db61866a3f48bd747ba7197f1be45bb1dfec940e3' 
  AND token = 'QR8KOXGH69kZtrkZkmsH7u3fTMCz317LgRULwzidTSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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