SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92636bc0a256ee6b4b50353176f3cd9eb56e4200819809865a720757205de112' 
  AND token = '54TOBH3utsDoMpNliehblCHbgQbxPJ61dAunuUM7bEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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