SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab20f73608af360a27978a7896ddc255d97783a1d189db3b4b5a105c035ca9b9' 
  AND token = 'P275GFYmbKjm4bxV9j56pLcQTAVE8WNQaiIsJxFnfOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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