SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '579552d3d8c3703a6026ab1c749e9cc550e36ecee0cc884f0ab1efe8f6c50d31' 
  AND token = 'A4fM8SZDuqloXX/N0dFtneQsnDXYbqlUmDQqrFVrNas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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