SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee542c929c9165dd8f4f6a795bf93f5af67b97aec184aaeabe6418f8413ad8d' 
  AND token = 'MZ04lkgPdj8fRpGKiwJBW+lOoZqD3jMGFluFWJLp6A8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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