SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '723da2d8cc454c779a9778427b2096caead7dc3e324be26ae313e4a85544ae53' 
  AND token = 'TaBIpWeOyN8JTEnPX06PLmPB74up4tJzqGiNCphuN2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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