SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab533ef9000af56406aa71d11b7e2ceab036678303198f28b4daa306caa76bf4' 
  AND token = 'Sogz6RCEguNlGWJLWPSu65nmua7mXbvoxSbxN3G+ThI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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