SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbfe7f98ad01d56e785e4ae6bfc4473bf61bacb481b5ebf3c628f0d72099d029' 
  AND token = 'G4dmWN5HmtgEPZ+GKhheLKDwbTbjX9nheJNkBT5JFCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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