SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cc84a23bbd20e444c32a5ce9fb4b5b1894f41adf2312392fec799ebd814862c' 
  AND token = 'iEnWz2Sl0RWAFnzyt1dbllKRNbRc+OTYCd13u7bCKHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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