SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27f8a6d3517ec4e12a23fd83edb786054745082c2af457d8a3962dc194c6216c' 
  AND token = 'NrvRd0aeEp8v3ObuefyzRvtDA6HhTZRucuRLD3DWDc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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