SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48d49347c859eaf54308b98a66915b585e0ed020d3dfec079909c61f8e1fe0a4' 
  AND token = 'rwCe9B2c5rapIg0FEyx++ifM80lihJZBR4mgOKkeb8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}