SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9357cba31ea7a43642c4557c8a432f0169a71881246fd744195fc1bc0362de2' 
  AND token = 'PXk+D5ZB5h7YLrnPxY7wsYJ7Gk+1pZIOpXBuJN/dbgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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