SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd7f1b2b07bf847ea35201c2f5b7a8d7dd7043a352b5e62edf089a71ed198fff' 
  AND token = '70MVMZKf0MjJy4pGWJq8NUuASvM3BIfuzkhZvs75Z5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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