SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0f2ffce1e8b0416dbe5b2315d5bfd40aca7fdd007d7959796165a24d0541c3' 
  AND token = 'YGBsJDvieKQQro3/orsZUbg7KVZ+c4QzwZr/Uo91iM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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