SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ffde8b4d032355f1f4e342fc70c38f274f40720955d9780113080874b9b9e03' 
  AND token = 'rTxZK3Cvaw+WLUDFTuJYogx8jYuIcHDk2LoSM7meUpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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