SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0717f9a1cc72d65dff017897b5d45b19fff437dfcc2c3cb1eb6c709f18b33fd' 
  AND token = 'IxzEoZq4PuK6G0EY3bck7NQzCztFWEDLVtmsUfxZmOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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