SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a2af35ed1899419c92548b1467e66204fe95ddf68d067630124d0e17ef3bb7c' 
  AND token = 'jchqVF7DZf3JFVJVnXFXHBv2n/YVjoN68Cr8LerUNkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00104

JSON explain

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