SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80628bd271104df6a12dc607f35370f14fc68d48c4eb0f159b184905033f0875' 
  AND token = 'Q9X9MrBmnzqPkgSEK0GdOw1pUdCrDu9Jo0UeUdIgDAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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