SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0f2f4babf376a874194ab60c0152abbf88cb1bffcedf36d46933e1995ef984f' 
  AND token = 'josy16T7hv9aEzxJnYgqdCUWwdvipXot6SHHx054RWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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