SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abd2ec73606e597ed718273975da33ccc3cf84c1b36f947e528818b333006078' 
  AND token = 'XOCSvmqVQVBs4WdS0glQffBXFzffElGPrLpqpb+xfK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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