SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bebbb06f08e0a0baebbdb90c62f20d187c48e3e7607f7d9d527fe5a775bcfb78' 
  AND token = 'VZPBiEgOdLt+fiCbFZ9jM/w5m1SyuoYCazsqgiOdwR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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