SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e425a78356221579258153a1c69de2772f72dc1eb6141bd49c055f168752ebb4' 
  AND token = 'I14pJJYnQ3njHC87HU70Pqcr7lIkxBUIxVI4hCsKGjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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