SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e45797a073f4ad12b756f566d760a3ebf611c96387858f2f780b334369ee245' 
  AND token = 'rsZevLsUyLZjmRFhhhmljMS3HNFx7s99xx8yxzoe0Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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