SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '346a6cc50383ac4f9b429387837b89d6f8509603958e79b386f71684a0f8dbff' 
  AND token = 'nZPVUck1iDcqEwHYsM7cRMcMEwzxzENjq5E+MQRWsVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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