SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1329af8bb4d93be857cb43c6fa74a001214d62a34637e297db3d38a8652caa89' 
  AND token = 'qHZPiMwXRagoTwjKpkw5Rm3+ACcEHoPR0ybzRtRNsvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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