SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcaa22175475eeecee2ed5b15857117e32f6f0693aee3079d153af09a48e6199' 
  AND token = 'vlnyTwzJ5Hgqk+vZ7wgpC1xiymIg/5Nj20DqZCLx/mY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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