SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '825ad21fe741966749cadbecfc2dfae90696820595ed7c98cbd75527cf52a11e' 
  AND token = 'M1LyGxoPIUT+ocREWvfdxAAGnMRcrcBcvi+tluLstkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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