SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c722a0b2064849f81c61eacd0358da7729087288cd330c22429bd286121dbe0d' 
  AND token = 'yt5HAPXEO+dWixC0F5KrEyT1z3cykgCOVA6cfVJSGmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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