SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b95206da0f65eeb2476f908e099fca3f8f59502c0af64ad4540ed1ca397bd4d0' 
  AND token = 'HXQczW3c9uilqq+7LmgPEY7wC/PbAexHGKLzvTT71Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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